Re: OT: Rock and Chips

On 12 Feb, 00:19, Kennedy McEwen <r...@xxxxxxxxxxxxxxxxxx> wrote:
In article
<f748dd19-5100-4053-9409-34c5a42eb...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"davidrobin...@xxxxxxxxxxxxxxxx" <davidrobin...@xxxxxxxxxxxxxxxx> writes

So now _again_ in your first paragraph you say the bluring is 20x
_less_ than a 100% shutter, and in your last paragraph you say the
bluring is _more_ than a 100% filter - make your mind up!

I did think you had enough comprehension to realise that these are
completely different things that are being compared.
1. The blurring of the individual 100% shuttered 1kHz frames is 20x less
than the blurring of a 100% shuttered 50Hz frame.

Yes, _that's_ right - pity it's _not_ what you said.

You said "No contradiction at all - read what I did: 1kHz frames at
100% shutter
downsampled to 50Hz by sinc-based weighting. That means each of the
adjacent *contiguous* blurred* images in the downsampled image *is*
20x
less blurred than a single 50Hz 100% shutter image would be."

See -" 20x less blur" "in the _downsampled_ image" is what you said.
It's not - it's in the 1kHz original that there's 20x less blur -
which is obvious, given a 20x shorter shutter!

You very carefully, and very clearly, said something that was
completely wrong.


So is this your speciality - a tenuous grasp of the bleeding obvious,
but an inability to write it down without fundamental basic errors?


 It is also less than
the blurring of a sinc (or sinc based) weighted average of a 50Hz frame.

2. The infinite extent (and also the non-infinite practical extent) of
sinc (or sinc based) weighted average is also *much* wider than the 100%
shutter.  The 100% shutter has 100% intensity across one 50fps frame
period, the weighted average has less than 100% intensity spanning many
50fps frame periods, and is consequently wider than the 100% shutter.

You claim to know this yet claim confusion - you are a demonstrable
idiot!

 If you knew what you were talking
about rather that just arguing for the sake of it then that simple fact
would have been obvious to you.

That part (the temporal extent of ideal sinc filtering) was _always_
obvious to me.

So you say, yet you still demonstrate inability to understand the
obvious as above.  If the temporal extent of the sinc is infinite, and
in practice it isn't since it eventually falls below the noise level,
then by definition it must be wider than 100% shutter.

The main lobe isn't though.

 I guess that's
the same intellectual problem that has you clinging to sinc, complete
with negative terms, requiring the existence of negative intensity and
energy.

It requires negative numbers for computation - it hardly requires a
negative input! Digital video leaves headroom in blacker-than-black
specifically for processing undershoots like this.


You simply don't understand what you are talking about and virtually
every argument you have put up demonstrates that, with increasing
clarity.

There is no point in discussing the matter further.

The fundamental papers I have, e.g...
http://www.stanford.edu/class/ee104/shannonpaper.pdf
...don't cover this.

Do you have something more recent in mind?

Who knows? Its certainly something more relevant than "404 file not
found"!  I suggest you try a library.

So the one marginally interesting claim you've made, and you can't
back it up?

Wow - what insight you have!

Cheers,
David.
.

Relevant Pages

  • Re: OT: Rock and Chips
    ... If the sampling isn't instantaneous, ... The temporal sinc function *is* a time averaged ... Conversely the frequency response of a rect function is a sinc ... A 100% shutter achieves this satisfactorily, as demonstrated by the fact that it has been in use since the invention of the television tube and *nobody* has ever needed to apply any temporal correction! ...
    (uk.tech.digital-tv)
  • Re: OT: Rock and Chips
    ... >So now _again_ in your first paragraph you say the bluring is 20x ... >_less_ than a 100% shutter, and in your last paragraph you say the ... The negative terms of the sinc correspond *directly* to required negative input signal and since the latter is impossible, the direct sinc function is obviously not the correct function in this case. ...
    (uk.tech.digital-tv)
  • Re: OT: Rock and Chips
    ... shutter creates a single blurred ball. ... Ideal sampling has a very ... specific meaning - you need a sinc filter. ...
    (uk.tech.digital-tv)
  • Re: OT: Rock and Chips
    ... It is also less than the blurring of a sinc weighted average of a 50Hz frame. ... The infinite extent of sinc weighted average is also *much* wider than the 100% shutter. ... The 100% shutter has 100% intensity across one 50fps frame period, the weighted average has less than 100% intensity spanning many 50fps frame periods, and is consequently wider than the 100% shutter. ...
    (uk.tech.digital-tv)
  • Re: Shooting Smart Slate on EX-1
    ... Well Most CCD cameras have an electronic shutter that allows the CCD to ... "Gather Light" on each pixel for a period of time equal to 1/2 the frame ... Only on fast pans where all pixels in the frame are changing from ... We're cross jamming another camera and all the numbers show up clear, ...
    (rec.arts.movies.production.sound)